aboutsummaryrefslogtreecommitdiffstats
path: root/lib/arel/visitors/to_sql.rb
blob: 2660c7d2849d6dce926300027c8e294b60e6328c (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
require 'bigdecimal'

module Arel
  module Visitors
    class ToSql
      def initialize engine
        @engine     = engine
        @connection = nil
      end

      def accept object
        @connection = @engine.connection
        visit object
      end

      private
      def visit_Arel_Nodes_DeleteStatement o
        [
          "DELETE FROM #{visit o.relation}",
          ("WHERE #{o.wheres.map { |x| visit x }.join ' AND '}" unless o.wheres.empty?)
        ].compact.join ' '
      end

      def visit_Arel_Nodes_UpdateStatement o
        [
          "UPDATE #{visit o.relation}",
          ("SET #{o.values.map { |value| visit value }.join ', '}" unless o.values.empty?),
          ("WHERE #{o.wheres.map { |x| visit x }.join ' AND '}" unless o.wheres.empty?)
        ].compact.join ' '
      end

      def visit_Arel_Nodes_InsertStatement o
        [
          "INSERT INTO #{visit o.relation}",

          ("(#{o.columns.map { |x|
                quote_column_name x.name
            }.join ', '})" unless o.columns.empty?),

          (visit o.values if o.values),
        ].compact.join ' '
      end

      def visit_Arel_Nodes_Values o
        "VALUES (#{o.expressions.map { |value|
          value.nil? ? 'NULL' : visit(value)
        }.join ', '})"
      end

      def visit_Arel_Nodes_SelectStatement o
        [
          o.cores.map { |x| visit x }.join,
          ("ORDER BY #{o.orders.map { |x| visit x }.join(', ')}" unless o.orders.empty?),
          ("LIMIT #{o.limit}" if o.limit),
          (visit(o.offset) if o.offset),
          (visit(o.lock) if o.lock),
        ].compact.join ' '
      end

      def visit_Arel_Nodes_SelectCore o
        [
          "SELECT #{o.projections.map { |x| visit x }.join ', '}",
          ("FROM #{o.froms.map { |x| visit x }.join ', ' }" unless o.froms.empty?),
          ("WHERE #{o.wheres.map { |x| visit x }.join ' AND ' }" unless o.wheres.empty?),
          ("GROUP BY #{o.groups.map { |x| visit x }.join ', ' }" unless o.groups.empty?),
          (visit(o.having) if o.having),
        ].compact.join ' '
      end

      def visit_Arel_Nodes_Having o
        "HAVING #{visit o.expr}"
      end

      def visit_Arel_Nodes_Offset o
        "OFFSET #{visit o.value}"
      end

      # FIXME: this does nothing on SQLLite3, but should do things on other
      # databases.
      def visit_Arel_Nodes_Lock o
      end

      def visit_Arel_Nodes_Group o
        visit o.expr
      end

      def visit_Arel_Nodes_Count o
        "COUNT(#{o.distinct ? 'DISTINCT ' : ''}#{o.expressions.map { |x|
          visit x
        }.join(', ')})#{o.alias ? " AS #{visit o.alias}" : ''}"
      end

      def visit_Arel_Nodes_Sum o
        "SUM(#{o.expressions.map { |x|
          visit x }.join(', ')})#{o.alias ? " AS #{visit o.alias}" : ''}"
      end

      def visit_Arel_Nodes_Max o
        "MAX(#{o.expressions.map { |x|
          visit x }.join(', ')})#{o.alias ? " AS #{visit o.alias}" : ''}"
      end

      def visit_Arel_Nodes_Min o
        "MIN(#{o.expressions.map { |x|
          visit x }.join(', ')})#{o.alias ? " AS #{visit o.alias}" : ''}"
      end

      def visit_Arel_Nodes_Avg o
        "AVG(#{o.expressions.map { |x|
          visit x }.join(', ')})#{o.alias ? " AS #{visit o.alias}" : ''}"
      end

      def visit_Arel_Nodes_TableAlias o
        "#{visit o.relation} #{quote_table_name o.name}"
      end

      def visit_Arel_Nodes_GreaterThanOrEqual o
        "#{visit o.left} >= #{visit o.right}"
      end

      def visit_Arel_Nodes_GreaterThan o
        "#{visit o.left} > #{visit o.right}"
      end

      def visit_Arel_Nodes_StringJoin o
        "#{visit o.left} #{visit o.right}"
      end

      def visit_Arel_Nodes_OuterJoin o
        "#{visit o.left} LEFT OUTER JOIN #{visit o.right} #{visit o.constraint}"
      end

      def visit_Arel_Nodes_InnerJoin o
        "#{visit o.left} INNER JOIN #{visit o.right} #{visit o.constraint if o.constraint}"
      end

      def visit_Arel_Nodes_On o
        "ON #{visit o.expr}"
      end

      def visit_Arel_Table o
        if o.table_alias
          "#{quote_table_name o.name} #{quote_table_name o.table_alias}"
        else
          quote_table_name o.name
        end
      end

      def visit_Arel_Nodes_In o
        "#{visit o.left} IN (#{o.right.map { |x| visit x }.join ', '})"
      end

      def visit_Arel_Nodes_And o
        "#{visit o.left} AND #{visit o.right}"
      end

      def visit_Arel_Nodes_Or o
        "#{visit o.left} OR #{visit o.right}"
      end

      def visit_Arel_Nodes_Assignment o
        right = o.right

        right = right.nil? ? 'NULL' : visit(right)
        "#{visit o.left} = #{right}"
      end

      def visit_Arel_Nodes_Equality o
        right = o.right

        if right.nil?
          "#{visit o.left} IS NULL"
        else
          "#{visit o.left} = #{visit right}"
        end
      end

      def visit_Arel_Nodes_NotEqual o
        right = o.right

        if right.nil?
          "#{visit o.left} IS NOT NULL"
        else
          "#{visit o.left} != #{visit right}"
        end
      end

      def visit_Arel_Nodes_UnqualifiedColumn o
        "#{quote_column_name o.name}"
      end

      def visit_Arel_Attributes_Attribute o
        join_name = o.relation.table_alias || o.relation.name
        "#{quote_table_name join_name}.#{quote_column_name o.name}"
      end
      alias :visit_Arel_Attributes_Integer :visit_Arel_Attributes_Attribute
      alias :visit_Arel_Attributes_String :visit_Arel_Attributes_Attribute
      alias :visit_Arel_Attributes_Time :visit_Arel_Attributes_Attribute
      alias :visit_Arel_Attributes_Boolean :visit_Arel_Attributes_Attribute

      def visit_Fixnum o; o end
      alias :visit_Arel_Nodes_SqlLiteral :visit_Fixnum
      alias :visit_Arel_SqlLiteral :visit_Fixnum # This is deprecated

      def visit_TrueClass o; quote(o) end
      def visit_String o; quote(o) end
      def visit_Hash o; quote(o) end
      def visit_ActiveSupport_Multibyte_Chars o; quote(o) end if defined?(ActiveSupport)
      def visit_Symbol o; quote(o) end
      def visit_Time o; quote(o) end
      def visit_Date o; quote(o) end
      def visit_DateTime o; quote(o) end
      def visit_Float o; quote(o) end
      def visit_BigDecimal o; quote(o) end
      def visit_FalseClass o; quote(o) end

      DISPATCH = {}
      def visit object
        send "visit_#{object.class.name.gsub('::', '_')}", object
        #send DISPATCH[object.class], object
      end

      private_instance_methods(false).each do |method|
        method = method.to_s
        next unless method =~ /^visit_(.*)$/
        const = $1.split('_').inject(Object) { |m,s| m.const_get s }
        DISPATCH[const] = method
      end

      def quote value, column = nil
        @connection.quote value, column
      end

      def quote_table_name name
        @connection.quote_table_name name
      end

      def quote_column_name name
        @connection.quote_column_name name
      end
    end
  end
end